Positive photoresist composition for exposure to far ultraviolet light

Abstract

A positive photoresist composition position for exposure to far ultraviolet light, which comprises a resin decomposing by the action of an acid to increase its solubility in an alkali, and a compound generating an acid by irradiation with an actinic ray or radiation; with the resin comprising repeating units having particular structures, including particular alicyclic structures, and groups decomposing by the action of an acid.

What is claimed is: 
     
       1. A positive photoresist composition for exposure to far ultraviolet light which comprises a resin decomposing by the action of an acid to increase its solubility in an alkali, and a compound generating an acid by irradiation with an actinic ray or radiation, said resin comprising a polymer that contains as repeating units both units represented by the following formula (I) and units represented by the following formula (II-A) or (II-B) and further has groups decomposing by the action of an acid: ##STR17## wherein R 1  and R 2  each independently represent a hydrogen atom, a cyano group, a hydroxyl group, --OOOH, --COOR 5 , --CO--NH--R 6 , --CO--NH--SO 2  --R 6 , a substituted or unsubstituted alkyl, alkoxy or cyclic hydrocarbon group, or a group --Y; R 5  represents a substituted or unsubstituted alkyl or cyclic hydrocarbon group, or a group --Y; the group --Y is represented by ##STR18## wherein R 21  to R 28  each independently represent a hydrogen atom or a substituted or unsubstituted alkyl group, and a and b are each 1 or 2; R 6  represents a substituted or unsubstituted alkyl or cyclic hydrocarbon group; X represents an oxygen atom, a sulfur atom, --NH--, --NHSO 2  --, or --NHSO 2  NH--; R 13  to R 16  each independently represent a hydrogen atom, a halogen atom a cyano group, --COOH, an acid-decomposable group, --C(═O)--X--A--R 17  or an unsubstituted or substituted alkyl or cyclic hydrocarbon group, or at least two of the substituents R 13  to R 16  combine with each other to form a ring; n is 0 or 1; R 17  represents --COOH, --COOR 5 , --CN, a hydroxyl group, an unsubstituted or substituted alkoxy group, --CO--NH--R 6 , --CO--NH--SO 2  --R 6  or the group --Y; and A represents a single bond or a divalent linkage group.